A train safety device including the on-board transponder device mentioned above is a device that transmits and receives a telegraph (a digital telegraph) between a ground device and an on-board device on a train side and execute train control according to contents described in the telegraph. In view of executing train control safely, the train safety device is required to reliably transmit a correct telegraph.
As a conventional device of this type, a train safety device is described in Patent Literature 1 mentioned below, for example (disclosed as “train control system” in Patent Literature 1). In the train safety device, a telegraph including a specific number allocated to a route from a certain stopping station from which a train starts to another stopping station different from the certain stopping station, and at which the train arrives, is transmitted mutually between an on-board device and a ground device to detect a stuck failure (also called “sticking failure”) that occurs due to a memory error or the like in respective processors, such as a transmission/reception device, interposed on a transmission line.